JP5686640B2 - Substrate processing apparatus and substrate processing method - Google Patents

Description

  The present invention relates to a substrate processing apparatus and a substrate processing method.

A semiconductor manufacturing apparatus generally has a plurality of processing chambers for processing a semiconductor substrate under reduced pressure or in vacuum. The semiconductor substrate is continuously introduced into the plurality of processing chambers according to a predetermined manufacturing process, and predetermined processing is performed.
Further, the processing chamber is normally kept in a vacuum before and after the start of a predetermined process according to the manufacturing process. Therefore, when a semiconductor substrate is carried into or out of the processing chamber, a load lock chamber for changing the pressure between vacuum and atmospheric pressure is required.

  As such a semiconductor manufacturing apparatus, a multi-chamber type semiconductor manufacturing apparatus has been frequently used in recent years. A multi-chamber semiconductor manufacturing apparatus is configured for one or a plurality of load lock chambers for accommodating a substrate to be processed and a substrate to be processed around a core chamber (transfer chamber) in which a substrate transfer robot is disposed. It has a structure in which a plurality of processing chambers for performing predetermined vacuum processing such as film and etching are arranged. The substrate is transferred between the load lock chamber and the processing chamber and the substrate is transferred between the processing chambers via a substrate transfer robot in the core chamber (see, for example, Patent Document 1).

  Here, a general transfer process of the semiconductor substrate to the processing chamber using the load lock chamber is as follows. The load lock chamber in which the semiconductor substrate is introduced from the atmosphere is evacuated and vacuumed. Subsequently, the semiconductor substrate is transferred from the load lock chamber to the processing chamber via the core chamber by the substrate transfer robot installed in the core chamber adjacent to the load lock chamber. Thereafter, processing operations (for example, etching, oxidation, chemical vapor deposition, etc.) are performed on the semiconductor substrate in the process chamber.

The semiconductor substrate after processing is returned from the processing chamber to the load lock chamber via the core chamber by the substrate transfer robot in the same manner as when transferring to the processing chamber. The load lock chamber is kept in a vacuum all the time after the transfer of the substrate from the load lock chamber to the processing chamber. After the semiconductor substrate returns to the load lock chamber, a purge gas such as nitrogen (N ₂ ) is supplied to return the pressure in the load lock chamber to atmospheric pressure (open to the atmosphere). After the pressure in the load lock chamber reaches atmospheric pressure, the processed semiconductor substrate is transferred to the substrate cassette and is used for the next processing step.

As described above, in the vacuum processing apparatus, since the substrate is always taken in and out through the load lock chamber, if the load lock chamber is opened to the atmosphere for a long time, the throughput of the load lock chamber decreases, and the processing capacity of the entire apparatus decreases. There was a problem.
When a predetermined gas is introduced into the load lock chamber and the load lock chamber is released from the vacuum state to the atmosphere, the pressure P in the load lock chamber gradually increases after the start of gas introduction, so P approaches the atmospheric pressure. As a result, the difference in pressure between the gas supply pressure and the load lock chamber is reduced, and the gas flow rate is reduced.
As a countermeasure, when the gas introduction pressure for releasing the load lock chamber to the atmosphere was increased, particles were generated at the time of gas introduction, and thus the pressure could not be increased beyond a certain level.

In addition, even in a device equipped with a filter to suppress particles, the gas introduction pressure can only be raised to the filter specification value, and there is a problem that the gas introduction time increases due to the gas conductance of the filter, and the whole device The throughput was load-lock limited.
In order to shorten the gas introduction time, in order to increase the gas flow rate, the gas introduction pressure is increased within a range where particles are not generated from the filter. However, further reduction of the gas introduction time has been desired.

JP 2009-206270 A

The present invention has been devised in view of such a conventional situation, and it is a first object of the present invention to provide a substrate processing apparatus in which the air release time is shortened and the throughput is improved.
In addition, a second object of the present invention is to provide a substrate processing method that shortens the time required for opening to the atmosphere and improves the throughput.

The substrate processing apparatus according to claim 1 of the present invention is a gas supply for introducing a predetermined gas into the chamber through a chamber, a stage placed in the chamber and on which a substrate is placed, and a gas supply line. Means, a pressure sensor for detecting the pressure P ₁ in the chamber, and a control means for controlling the gas introduction pressure P ₂ , wherein the gas supply means introduces a predetermined gas into the chamber. said chamber by introducing at P ₂ when exposed to the atmosphere from the vacuum state, wherein the pressure sensor detects a pressure P ₁ in the chamber, said control means, with respect to the P _1, and the P ₂ as the difference between P ₁ is substantially constant, by controlling the P _2, characterized.
A substrate processing apparatus according to a second aspect of the present invention is the substrate processing apparatus according to the first aspect, further comprising a filter that is disposed in a gas supply line of the gas supply unit and suppresses particles.
According to a third aspect of the present invention, there is provided the substrate processing apparatus according to the first or second aspect, further comprising a buffer that is disposed in the gas supply line of the gas supply unit and retains the gas.
According to a fourth aspect of the present invention, there is provided a substrate processing method, comprising: a chamber; a stage placed in the chamber and on which a substrate is placed; a gas supply means for introducing a predetermined gas into the chamber; and the chamber a pressure sensor for detecting the pressure P ₁ of the inner, and control means for controlling the introduction pressure P ₂ of the gas, the substrate processing method using the substrate processing apparatus having a, introducing a predetermined gas into the chamber When the chamber is opened from the vacuum state to the atmosphere, the pressure P ₁ in the chamber is detected, and the difference between the P ₂ and the P ₁ is substantially constant with respect to the P ₁ . controlling the P _2, characterized.

The substrate processing apparatus of the present invention, the gas supply means, said chamber by introducing a predetermined gas into the chamber at the introduction pressure P ₂ at the time of air release from the vacuum state, the control means is in the P ₁ in contrast, the difference between the P ₁ and the P ₂ are such that substantially constant, and controls the gas introduction pressure P _2. Wherein P ₂ and it is possible to always maintain the same gas flow rate difference between the P ₁ by a substantially constant, thereby making it possible to increase the speed of the air release rate. As a result, according to the present invention, it is possible to provide a substrate processing apparatus in which the time for opening to the atmosphere is shortened, the throughput is improved, and as a result, the processing efficiency of the entire apparatus is improved.
In the substrate processing method of the present invention, when the predetermined gas is introduced into the chamber at the introduction pressure P ₂ and the chamber is released from the vacuum to the atmosphere, the P ₂ and the P ₁ are compared with the P _1. difference is such that substantially constant, and controls the gas introduction pressure P ₂ and. The difference between P ₂ and the P ₁ is able to maintain always the same gas flow rate becomes almost constant, thereby making it possible to increase the speed of the air release rate. As a result, according to the present invention, it is possible to provide a substrate processing method in which the open time to the atmosphere is shortened, the throughput is improved, and the overall processing efficiency is improved.

The schematic block diagram of the vacuum processing apparatus of the multi-chamber system to which this invention is applied. Sectional drawing which shows typically an example of the substrate processing apparatus which concerns on this invention. Sectional drawing which shows typically another example of the substrate processing apparatus which concerns on this invention. The substrate processing apparatus (load lock chamber) when exposed to the atmosphere, shows the internal pressure P ₁ and the gas introducing pressure P ₂ chamber, the relationship between the time FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a substrate processing apparatus and a substrate processing method according to the present invention will be described with reference to the drawings.

  In the present embodiment, the case where the present invention is applied to a load lock chamber in a multi-chamber vacuum processing apparatus will be described as an example. However, the present invention is not limited to this, and various substrates are used. It can be applied to a processing apparatus. Here, the load lock chamber is an apparatus that is connected to the transfer chamber and is used when a processed substrate is taken out from the chamber.

  FIG. 1 is a schematic configuration diagram of a multi-chamber type vacuum processing apparatus 1 according to an embodiment of the present invention. The vacuum processing apparatus 1 includes load lock chambers 3A and 3B (3) for accommodating a substrate to be processed (hereinafter also simply referred to as “substrate”), and processing chambers 4A to 4D (for performing predetermined vacuum processing on the substrate). 4) and a core chamber (transfer chamber) 5 for transferring the substrate between the load lock chambers 3A and 3B and the processing chambers 4A to 4D.

  The load lock chambers 3A and 3B (3) have the same configuration, and a substrate stocker (not shown) capable of accommodating a predetermined number of substrates is installed therein. Exhaust systems are connected to the load lock chambers 3A and 3B, respectively, and can be evacuated independently of each other. The load lock chambers 3A and 3B are not limited to being installed as in the illustrated example, and may be singular.

  The processing chambers 4A to 4D (4) are configured by an etching chamber, a heating chamber, a film forming chamber (a sputtering chamber, a CVD chamber), and the like, and all of them are film forming chambers in this embodiment. An exhaust system (not shown) is connected to each of the processing chambers 4A to 4D, and can be evacuated independently of each other. Each processing chamber 4A to 4D is connected to a gas supply source (not shown) of a predetermined film forming gas (reaction gas, source gas, inert gas, etc.) corresponding to the process.

  The core chamber 5 has a substrate transfer robot 6 therein, and the substrate 2 is transferred between the load lock chambers 3A and 3B and the processing chambers 4A to 4D or between the processing chambers 4A to 4D. It is configured. An exhaust system (not shown) is connected to the core chamber 5 and can be evacuated independently. In addition, a gas source (not shown) is connected to the core chamber 5 so that the core chamber 5 can be maintained at a predetermined pressure by a pressure-controlled gas introduced from the gas source.

FIG. 2 is a cross-sectional view schematically showing a configuration example of the substrate processing apparatus according to the present invention in the load lock chamber 3.
The substrate processing apparatus 10 according to the present invention includes a chamber 11, a stage 12 disposed in the chamber 11, a stage 12 on which the substrate 2 is placed, and a gas for introducing a predetermined gas into the chamber 11 through a gas supply line 13 a. provided with supply means 13, a pressure sensor 15 for detecting the pressure P ₁ in the chamber 11, and a control means for controlling the gas introduction pressure P _2.

  An exhaust means 14 is connected to the chamber 11 and can be evacuated independently. A gas supply means 13 is connected to the chamber 11 and can be maintained at a predetermined pressure by the gas introduced from the gas supply means 13.

The stage 12 is disposed in the chamber 11 and the substrate 2 is placed on the surface 12a.
The stage 12 is provided with a plurality of through holes 19, and elevating pins 20 for raising and lowering the substrate 2 are inserted into the through holes so as to be able to project and retract with respect to the surface (upper surface) of the stage 12. Has been. The elevating pins 20 are fixed to a rod 21 and are connected to a driving mechanism 23 such as an air cylinder via a bellows 22 that can be expanded and contracted.

  Then, when the substrate 2 is transferred by moving the rod 21 up and down by a driving mechanism 23 such as an air cylinder, the lifting pins 20 are projected from the surface (upper surface) of the stage 12, and the substrate 2 is moved to the surface 12 a of the stage 12. In the case of mounting on the (upper surface), the lifting pins 20 are recessed from the surface 12 a (upper surface) of the stage 12.

The gas supply means 13 introduces a predetermined gas into the chamber 11 through the gas supply line 13a, for example, when the chamber 11 is released from the vacuum state to the atmosphere. The gas introduced by the gas supply means 13 is not particularly limited, and examples thereof include chemically stable gases such as nitrogen, argon, helium, and xenon.
A VENT valve 13b is arranged in the middle of the gas supply line 13a.

The pressure sensor 15 monitors the pressure (P ₁ ) in the chamber 11.
An electronic gas pressure controller (APR: auto pressure regulator) 16 controls the pressure of the gas introduced into the chamber 11 from the gas supply means 13. APR controls the gas introduction pressure P ₂ in the gas supply line 13a, thereby controlling the pressure of the gas introduced into the chamber 11.
The pressure sensor 15 and the electronic gas pressure controller (APR) 16 are connected via, for example, a computer 17.
Moreover, you may use the apparatus (for example, MFC: mass flow controller) which measures and controls the mass flow rate of the fluid instead of APR. With MFC, the flow rate can be controlled directly.

In such a multi-chamber type vacuum processing apparatus 1, a general transfer process of the substrate 2 to the processing chamber using the load lock chamber 3 is as follows.
First, the load lock chamber 3 into which the substrate 2 has been introduced from the atmosphere is evacuated to a vacuum. Subsequently, the substrate 2 is transferred from the load lock chamber 3 to the processing chamber 4 via the core chamber 5 by the substrate transfer robot 6 installed in the core chamber 5 adjacent to the load lock chamber 3. Thereafter, processing operations (for example, etching, oxidation, chemical vapor deposition, etc.) are performed on the substrate 2 in the processing chamber 4 (process chamber).

The substrate 2 after processing is returned from the processing chamber via the core chamber 5 to the load lock chamber 3 by the substrate transfer robot 6 in the same manner as when transferring to the processing chamber 4. The load lock chamber 3 is kept in a vacuum all the time after the transfer of the substrate from the load lock chamber 3 to the processing chamber 4 described above. After the substrate 2 returns to the load lock chamber 3, the gas supply means 13 opens the VENT valve 13b and supplies a purge gas such as nitrogen (N ₂ ) to return the pressure of the load lock chamber 3 to atmospheric pressure (open to the atmosphere). . After the pressure in the load lock chamber 3 reaches the atmospheric pressure, the processed substrate 2 is transferred to the substrate cassette and used for the next processing step.

Here, as an example when the load lock chamber 3 is opened to the atmosphere, for example, the pressure in the chamber 11 of the load lock chamber 3 is about 10 ⁻² Pa, and can be ignored as almost “0 (zero)” in the calculation. The atmospheric pressure is 0.1 MPa. The volume of the chamber 11 is 10L.
Therefore, it is necessary to introduce a gas of 10 L × 0.1 MPa to bring the load lock chamber 3 to atmospheric pressure. In addition, the said numerical value is an example and is not limited to this.

Here, FIG. 3 is a graph showing the change in pressure P ₁ and the gas introducing pressure P ₂ in the chamber 11 during the air release, the relationship between the time. Conventionally, in the load lock chamber 3, the chamber 11 by introducing a predetermined gas into the chamber 11 when exposed to the atmosphere from the vacuum state, as shown in FIG. 3, the gas introduction pressure P ₂ is constant. Since the pressure P ₁ in the chamber 11 gradually increases after starting the gas introduction, when P ₁ approaches the atmospheric pressure, the differential pressure between the pressure P ₁ and the gas introduction pressure P ₂ decreases, and the gas flow rate decreases. I was sorry. As a result, the pressure increase rate in the chamber decreases, and it takes 14 seconds to release the atmosphere.
Thus, in the vacuum processing apparatus, since the substrate is always taken in and out through the load lock chamber, if the load lock chamber is opened to the atmosphere for a long time, the throughput of the load lock chamber 3 is reduced, and the processing capacity of the entire apparatus is reduced. There was a problem that would decrease.

In contrast, in the present invention, in the substrate processing apparatus 10 (the load lock chamber 3), the gas supply means 13, the chamber by introducing a predetermined gas in the introduction pressure P ₂ from the vacuum state in the chamber 11 when exposed to the atmosphere, the pressure sensor 15 detects the pressure _{P 1} in the chamber 11, the control means (gas flow meter 16), relative to the _{P 1,} wherein _{P 2} and between the _{P 1} so that the difference is substantially constant, and controls the P _2.

As shown in FIG. 4, in the present invention, according to the pressure P ₁ in the chamber 11 rises, and the gas introduction pressure P ₂ is also increased. Here, so as to maintain the differential pressure _{P 1} to 1.1 (pressure), and controls the _{P 2.}
Wherein P ₂ and it is possible to always maintain the same gas flow rate difference between the P ₁ by a substantially constant, thereby maintaining a constant pressure rise rate. As a result, the air release rate can be increased. In the example shown in FIG. 4, atmospheric release can be completed in 10 seconds according to the present invention. As a result, according to the present invention, it is possible to shorten the time for opening to the atmosphere, improve the throughput, and improve the processing efficiency of the entire apparatus.

  A computer (not shown) that controls the apparatus determines that the load lock chamber 3 is in a state in which the substrate can be transported when it receives information that the pressure in the load lock chamber 3 has reached atmospheric pressure (air release has been completed). The VENT valve 13b is closed, and the substrate 2 that has been processed by the atmosphere-side transfer robot 6 in the transfer chamber 5 is transferred (unloaded) to the substrate cassette to be used for the next processing step.

  The substrate processing apparatus 10 of the present invention may further include a filter 30 that is disposed in the gas supply line 13a of the gas supply unit 13 and suppresses particles. By providing the filter 30 in the gas supply line 13a, it is possible to prevent the generation of particles when introducing the gas. As such a filter 30, for example, a filter made of a ceramic sintered body can be used. When the filter 30 is disposed, the filter 30 is installed between the gas flow meter 16 and the VENT valve 13b.

  Furthermore, the substrate processing apparatus 10 of the present invention may further include a buffer 13c that is disposed in the gas supply line 13a of the gas supply means 13 and retains the gas (FIG. 3). By providing the buffer 13c in the gas supply line 13a, the pressure drop can be suppressed. Moreover, the same effect can be acquired also by using piping thicker than usual for piping of the gas supply line 13a. For example, when a pipe having a diameter of 6.35 mm (1/4 inch φ) is normally used, a pipe having a diameter of 9.5 mm (3/8 inch φ) is used. In addition, the numerical value of a pipe diameter is not limited to this.

As described above, in the present invention, the chamber 11 by introducing a predetermined gas in the introduction pressure P ₂ in the chamber 11 when exposed to the atmosphere from the vacuum state, the pressure P ₁ in the chamber 11, By controlling the gas introduction pressure P ₂ so that the difference between the P ₂ and the P ₁ is substantially constant, the same gas flow rate can be always maintained. As a result, the atmospheric release speed can be increased. As a result, according to the present invention, it is possible to shorten the time for opening to the atmosphere, improve the throughput, and consequently improve the overall processing efficiency.

In the above-described embodiment, when the chamber is opened from the vacuum state to the atmosphere, the pressure sensor detects the pressure P ₁ in the chamber, and the control means controls the gas introduction pressure P ₂ according to P _1. has been described as an example, the present invention, a pressure sensor for detecting the pressure P ₁ may not necessarily comprise.
That is, when the chamber is released from the vacuum state to the atmosphere, if the relationship between the amount of gas introduced per unit time and the elapsed time from the start of gas introduction is known in advance, the control means can determine the gas introduction pressure based on this relationship. it is also possible to control the P _2. For example, if a PC control unit with a storage device, in a state where the storage device is accumulated as the information of the above relationship, PC and the like is configured to control the gas introduction pressure P _2.

  The substrate processing apparatus and the substrate processing method of the present invention have been described above, but the present invention is not limited to the above-described examples, and can be appropriately changed without departing from the spirit of the invention.

  The present invention can be applied to a substrate processing apparatus for various dry processes as long as it is a substrate processing apparatus including a load lock chamber regardless of whether it is a laboratory machine or a mass production machine.

  DESCRIPTION OF SYMBOLS 1 Vacuum processing apparatus, 2 Substrate, 3A, 3B (3) Load lock chamber, 4A-4D (4) Processing chamber, 5 core chamber (transfer chamber), 6 Substrate transfer robot, 10 Substrate processing apparatus, 11 Chamber, 12 Stage , 13 Gas supply means, 13a Gas supply line, 13b VENT valve, 14 Exhaust means, 15 Pressure sensor, 16 Gas flow meter (control means), 17 Computer, 30 Filter.

Claims (4)

A chamber;
A stage disposed in the chamber and on which a substrate is placed;
Gas supply means for introducing a predetermined gas into the chamber through a gas supply line;
A pressure sensor for detecting the pressure P ₁ in the chamber;
And a control means for controlling the introduction pressure P ₂ of the gas,
The gas supply means, said chamber by introducing a predetermined gas into the chamber at the introduction pressure P ₂ at the time of air release from the vacuum state,
The pressure sensor detects a pressure P ₁ in the chamber;
Wherein, relative to the P _1, wherein as the difference P ₂ and the P ₁ is substantially constant, the substrate processing apparatus, characterized in that, for controlling the P _2.   The substrate processing apparatus according to claim 1, further comprising a filter that is disposed in a gas supply line of the gas supply unit and suppresses particles.   The substrate processing apparatus according to claim 1, further comprising a buffer that is disposed in a gas supply line of the gas supply unit and retains the gas. A chamber, a stage placed in the chamber and on which a substrate is placed, a gas supply means for introducing a predetermined gas into the chamber, a pressure sensor for detecting the pressure P ₁ in the chamber, and the gas A substrate processing method using a substrate processing apparatus comprising: a control means for controlling the introduction pressure P ₂ of
The said introducing a predetermined gas into the chamber the chamber when opened to the atmosphere from the vacuum state, to detect the pressure P ₁ in the chamber,
The substrate processing method, wherein the P ₂ is controlled so that the difference between the P ₂ and the P ₁ is substantially constant with respect to the P ₁ .

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